xref: /freebsd/sys/kern/kern_linker.c (revision 39beb93c3f8bdbf72a61fda42300b5ebed7390c8)
1 /*-
2  * Copyright (c) 1997-2000 Doug Rabson
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include "opt_ddb.h"
31 #include "opt_hwpmc_hooks.h"
32 #include "opt_mac.h"
33 
34 #include <sys/param.h>
35 #include <sys/kernel.h>
36 #include <sys/systm.h>
37 #include <sys/malloc.h>
38 #include <sys/sysproto.h>
39 #include <sys/sysent.h>
40 #include <sys/priv.h>
41 #include <sys/proc.h>
42 #include <sys/lock.h>
43 #include <sys/mutex.h>
44 #include <sys/sx.h>
45 #include <sys/module.h>
46 #include <sys/mount.h>
47 #include <sys/linker.h>
48 #include <sys/fcntl.h>
49 #include <sys/libkern.h>
50 #include <sys/namei.h>
51 #include <sys/vnode.h>
52 #include <sys/syscallsubr.h>
53 #include <sys/sysctl.h>
54 #include <sys/vimage.h>
55 
56 #include <security/mac/mac_framework.h>
57 
58 #include "linker_if.h"
59 
60 #ifdef HWPMC_HOOKS
61 #include <sys/pmckern.h>
62 #endif
63 
64 #ifdef KLD_DEBUG
65 int kld_debug = 0;
66 #endif
67 
68 #define	KLD_LOCK()		sx_xlock(&kld_sx)
69 #define	KLD_UNLOCK()		sx_xunlock(&kld_sx)
70 #define	KLD_LOCKED()		sx_xlocked(&kld_sx)
71 #define	KLD_LOCK_ASSERT() do {						\
72 	if (!cold)							\
73 		sx_assert(&kld_sx, SX_XLOCKED);				\
74 } while (0)
75 
76 /*
77  * static char *linker_search_path(const char *name, struct mod_depend
78  * *verinfo);
79  */
80 static const char 	*linker_basename(const char *path);
81 
82 /*
83  * Find a currently loaded file given its filename.
84  */
85 static linker_file_t linker_find_file_by_name(const char* _filename);
86 
87 /*
88  * Find a currently loaded file given its file id.
89  */
90 static linker_file_t linker_find_file_by_id(int _fileid);
91 
92 /* Metadata from the static kernel */
93 SET_DECLARE(modmetadata_set, struct mod_metadata);
94 
95 MALLOC_DEFINE(M_LINKER, "linker", "kernel linker");
96 
97 linker_file_t linker_kernel_file;
98 
99 static struct sx kld_sx;	/* kernel linker lock */
100 
101 /*
102  * Load counter used by clients to determine if a linker file has been
103  * re-loaded. This counter is incremented for each file load.
104  */
105 static int loadcnt;
106 
107 static linker_class_list_t classes;
108 static linker_file_list_t linker_files;
109 static int next_file_id = 1;
110 static int linker_no_more_classes = 0;
111 
112 #define	LINKER_GET_NEXT_FILE_ID(a) do {					\
113 	linker_file_t lftmp;						\
114 									\
115 	KLD_LOCK_ASSERT();						\
116 retry:									\
117 	TAILQ_FOREACH(lftmp, &linker_files, link) {			\
118 		if (next_file_id == lftmp->id) {			\
119 			next_file_id++;					\
120 			goto retry;					\
121 		}							\
122 	}								\
123 	(a) = next_file_id;						\
124 } while(0)
125 
126 
127 /* XXX wrong name; we're looking at version provision tags here, not modules */
128 typedef TAILQ_HEAD(, modlist) modlisthead_t;
129 struct modlist {
130 	TAILQ_ENTRY(modlist) link;	/* chain together all modules */
131 	linker_file_t   container;
132 	const char 	*name;
133 	int             version;
134 };
135 typedef struct modlist *modlist_t;
136 static modlisthead_t found_modules;
137 
138 static int	linker_file_add_dependency(linker_file_t file,
139 		    linker_file_t dep);
140 static caddr_t	linker_file_lookup_symbol_internal(linker_file_t file,
141 		    const char* name, int deps);
142 static int	linker_load_module(const char *kldname,
143 		    const char *modname, struct linker_file *parent,
144 		    struct mod_depend *verinfo, struct linker_file **lfpp);
145 static modlist_t modlist_lookup2(const char *name, struct mod_depend *verinfo);
146 
147 static char *
148 linker_strdup(const char *str)
149 {
150 	char *result;
151 
152 	if ((result = malloc((strlen(str) + 1), M_LINKER, M_WAITOK)) != NULL)
153 		strcpy(result, str);
154 	return (result);
155 }
156 
157 static void
158 linker_init(void *arg)
159 {
160 
161 	sx_init(&kld_sx, "kernel linker");
162 	TAILQ_INIT(&classes);
163 	TAILQ_INIT(&linker_files);
164 }
165 
166 SYSINIT(linker, SI_SUB_KLD, SI_ORDER_FIRST, linker_init, 0);
167 
168 static void
169 linker_stop_class_add(void *arg)
170 {
171 
172 	linker_no_more_classes = 1;
173 }
174 
175 SYSINIT(linker_class, SI_SUB_KLD, SI_ORDER_ANY, linker_stop_class_add, NULL);
176 
177 int
178 linker_add_class(linker_class_t lc)
179 {
180 
181 	/*
182 	 * We disallow any class registration past SI_ORDER_ANY
183 	 * of SI_SUB_KLD.  We bump the reference count to keep the
184 	 * ops from being freed.
185 	 */
186 	if (linker_no_more_classes == 1)
187 		return (EPERM);
188 	kobj_class_compile((kobj_class_t) lc);
189 	((kobj_class_t)lc)->refs++;	/* XXX: kobj_mtx */
190 	TAILQ_INSERT_TAIL(&classes, lc, link);
191 	return (0);
192 }
193 
194 static void
195 linker_file_sysinit(linker_file_t lf)
196 {
197 	struct sysinit **start, **stop, **sipp, **xipp, *save;
198 
199 	KLD_DPF(FILE, ("linker_file_sysinit: calling SYSINITs for %s\n",
200 	    lf->filename));
201 
202 	if (linker_file_lookup_set(lf, "sysinit_set", &start, &stop, NULL) != 0)
203 		return;
204 	/*
205 	 * Perform a bubble sort of the system initialization objects by
206 	 * their subsystem (primary key) and order (secondary key).
207 	 *
208 	 * Since some things care about execution order, this is the operation
209 	 * which ensures continued function.
210 	 */
211 	for (sipp = start; sipp < stop; sipp++) {
212 		for (xipp = sipp + 1; xipp < stop; xipp++) {
213 			if ((*sipp)->subsystem < (*xipp)->subsystem ||
214 			    ((*sipp)->subsystem == (*xipp)->subsystem &&
215 			    (*sipp)->order <= (*xipp)->order))
216 				continue;	/* skip */
217 			save = *sipp;
218 			*sipp = *xipp;
219 			*xipp = save;
220 		}
221 	}
222 
223 	/*
224 	 * Traverse the (now) ordered list of system initialization tasks.
225 	 * Perform each task, and continue on to the next task.
226 	 */
227 	mtx_lock(&Giant);
228 	for (sipp = start; sipp < stop; sipp++) {
229 		if ((*sipp)->subsystem == SI_SUB_DUMMY)
230 			continue;	/* skip dummy task(s) */
231 
232 		/* Call function */
233 		(*((*sipp)->func)) ((*sipp)->udata);
234 	}
235 	mtx_unlock(&Giant);
236 }
237 
238 static void
239 linker_file_sysuninit(linker_file_t lf)
240 {
241 	struct sysinit **start, **stop, **sipp, **xipp, *save;
242 
243 	KLD_DPF(FILE, ("linker_file_sysuninit: calling SYSUNINITs for %s\n",
244 	    lf->filename));
245 
246 	if (linker_file_lookup_set(lf, "sysuninit_set", &start, &stop,
247 	    NULL) != 0)
248 		return;
249 
250 	/*
251 	 * Perform a reverse bubble sort of the system initialization objects
252 	 * by their subsystem (primary key) and order (secondary key).
253 	 *
254 	 * Since some things care about execution order, this is the operation
255 	 * which ensures continued function.
256 	 */
257 	for (sipp = start; sipp < stop; sipp++) {
258 		for (xipp = sipp + 1; xipp < stop; xipp++) {
259 			if ((*sipp)->subsystem > (*xipp)->subsystem ||
260 			    ((*sipp)->subsystem == (*xipp)->subsystem &&
261 			    (*sipp)->order >= (*xipp)->order))
262 				continue;	/* skip */
263 			save = *sipp;
264 			*sipp = *xipp;
265 			*xipp = save;
266 		}
267 	}
268 
269 	/*
270 	 * Traverse the (now) ordered list of system initialization tasks.
271 	 * Perform each task, and continue on to the next task.
272 	 */
273 	mtx_lock(&Giant);
274 	for (sipp = start; sipp < stop; sipp++) {
275 		if ((*sipp)->subsystem == SI_SUB_DUMMY)
276 			continue;	/* skip dummy task(s) */
277 
278 		/* Call function */
279 		(*((*sipp)->func)) ((*sipp)->udata);
280 	}
281 	mtx_unlock(&Giant);
282 }
283 
284 static void
285 linker_file_register_sysctls(linker_file_t lf)
286 {
287 	struct sysctl_oid **start, **stop, **oidp;
288 
289 	KLD_DPF(FILE,
290 	    ("linker_file_register_sysctls: registering SYSCTLs for %s\n",
291 	    lf->filename));
292 
293 	if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0)
294 		return;
295 
296 	sysctl_lock();
297 	for (oidp = start; oidp < stop; oidp++)
298 		sysctl_register_oid(*oidp);
299 	sysctl_unlock();
300 }
301 
302 static void
303 linker_file_unregister_sysctls(linker_file_t lf)
304 {
305 	struct sysctl_oid **start, **stop, **oidp;
306 
307 	KLD_DPF(FILE, ("linker_file_unregister_sysctls: registering SYSCTLs"
308 	    " for %s\n", lf->filename));
309 
310 	if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0)
311 		return;
312 
313 	sysctl_lock();
314 	for (oidp = start; oidp < stop; oidp++)
315 		sysctl_unregister_oid(*oidp);
316 	sysctl_unlock();
317 }
318 
319 static int
320 linker_file_register_modules(linker_file_t lf)
321 {
322 	struct mod_metadata **start, **stop, **mdp;
323 	const moduledata_t *moddata;
324 	int first_error, error;
325 
326 	KLD_DPF(FILE, ("linker_file_register_modules: registering modules"
327 	    " in %s\n", lf->filename));
328 
329 	if (linker_file_lookup_set(lf, "modmetadata_set", &start,
330 	    &stop, NULL) != 0) {
331 		/*
332 		 * This fallback should be unnecessary, but if we get booted
333 		 * from boot2 instead of loader and we are missing our
334 		 * metadata then we have to try the best we can.
335 		 */
336 		if (lf == linker_kernel_file) {
337 			start = SET_BEGIN(modmetadata_set);
338 			stop = SET_LIMIT(modmetadata_set);
339 		} else
340 			return (0);
341 	}
342 	first_error = 0;
343 	for (mdp = start; mdp < stop; mdp++) {
344 		if ((*mdp)->md_type != MDT_MODULE)
345 			continue;
346 		moddata = (*mdp)->md_data;
347 		KLD_DPF(FILE, ("Registering module %s in %s\n",
348 		    moddata->name, lf->filename));
349 		error = module_register(moddata, lf);
350 		if (error) {
351 			printf("Module %s failed to register: %d\n",
352 			    moddata->name, error);
353 			if (first_error == 0)
354 				first_error = error;
355 		}
356 	}
357 	return (first_error);
358 }
359 
360 static void
361 linker_init_kernel_modules(void)
362 {
363 
364 	linker_file_register_modules(linker_kernel_file);
365 }
366 
367 SYSINIT(linker_kernel, SI_SUB_KLD, SI_ORDER_ANY, linker_init_kernel_modules,
368     0);
369 
370 static int
371 linker_load_file(const char *filename, linker_file_t *result)
372 {
373 	linker_class_t lc;
374 	linker_file_t lf;
375 	int foundfile, error;
376 
377 	/* Refuse to load modules if securelevel raised */
378 	if (securelevel > 0)
379 		return (EPERM);
380 
381 	KLD_LOCK_ASSERT();
382 	lf = linker_find_file_by_name(filename);
383 	if (lf) {
384 		KLD_DPF(FILE, ("linker_load_file: file %s is already loaded,"
385 		    " incrementing refs\n", filename));
386 		*result = lf;
387 		lf->refs++;
388 		return (0);
389 	}
390 	foundfile = 0;
391 	error = 0;
392 
393 	/*
394 	 * We do not need to protect (lock) classes here because there is
395 	 * no class registration past startup (SI_SUB_KLD, SI_ORDER_ANY)
396 	 * and there is no class deregistration mechanism at this time.
397 	 */
398 	TAILQ_FOREACH(lc, &classes, link) {
399 		KLD_DPF(FILE, ("linker_load_file: trying to load %s\n",
400 		    filename));
401 		error = LINKER_LOAD_FILE(lc, filename, &lf);
402 		/*
403 		 * If we got something other than ENOENT, then it exists but
404 		 * we cannot load it for some other reason.
405 		 */
406 		if (error != ENOENT)
407 			foundfile = 1;
408 		if (lf) {
409 			error = linker_file_register_modules(lf);
410 			if (error == EEXIST) {
411 				linker_file_unload(lf, LINKER_UNLOAD_FORCE);
412 				return (error);
413 			}
414 			KLD_UNLOCK();
415 			linker_file_register_sysctls(lf);
416 			linker_file_sysinit(lf);
417 			KLD_LOCK();
418 			lf->flags |= LINKER_FILE_LINKED;
419 			*result = lf;
420 			return (0);
421 		}
422 	}
423 	/*
424 	 * Less than ideal, but tells the user whether it failed to load or
425 	 * the module was not found.
426 	 */
427 	if (foundfile) {
428 
429 		/*
430 		 * If the file type has not been recognized by the last try
431 		 * printout a message before to fail.
432 		 */
433 		if (error == ENOSYS)
434 			printf("linker_load_file: Unsupported file type\n");
435 
436 		/*
437 		 * Format not recognized or otherwise unloadable.
438 		 * When loading a module that is statically built into
439 		 * the kernel EEXIST percolates back up as the return
440 		 * value.  Preserve this so that apps like sysinstall
441 		 * can recognize this special case and not post bogus
442 		 * dialog boxes.
443 		 */
444 		if (error != EEXIST)
445 			error = ENOEXEC;
446 	} else
447 		error = ENOENT;		/* Nothing found */
448 	return (error);
449 }
450 
451 int
452 linker_reference_module(const char *modname, struct mod_depend *verinfo,
453     linker_file_t *result)
454 {
455 	modlist_t mod;
456 	int error;
457 
458 	KLD_LOCK();
459 	if ((mod = modlist_lookup2(modname, verinfo)) != NULL) {
460 		*result = mod->container;
461 		(*result)->refs++;
462 		KLD_UNLOCK();
463 		return (0);
464 	}
465 
466 	error = linker_load_module(NULL, modname, NULL, verinfo, result);
467 	KLD_UNLOCK();
468 	return (error);
469 }
470 
471 int
472 linker_release_module(const char *modname, struct mod_depend *verinfo,
473     linker_file_t lf)
474 {
475 	modlist_t mod;
476 	int error;
477 
478 	KLD_LOCK();
479 	if (lf == NULL) {
480 		KASSERT(modname != NULL,
481 		    ("linker_release_module: no file or name"));
482 		mod = modlist_lookup2(modname, verinfo);
483 		if (mod == NULL) {
484 			KLD_UNLOCK();
485 			return (ESRCH);
486 		}
487 		lf = mod->container;
488 	} else
489 		KASSERT(modname == NULL && verinfo == NULL,
490 		    ("linker_release_module: both file and name"));
491 	error =	linker_file_unload(lf, LINKER_UNLOAD_NORMAL);
492 	KLD_UNLOCK();
493 	return (error);
494 }
495 
496 static linker_file_t
497 linker_find_file_by_name(const char *filename)
498 {
499 	linker_file_t lf;
500 	char *koname;
501 
502 	koname = malloc(strlen(filename) + 4, M_LINKER, M_WAITOK);
503 	sprintf(koname, "%s.ko", filename);
504 
505 	KLD_LOCK_ASSERT();
506 	TAILQ_FOREACH(lf, &linker_files, link) {
507 		if (strcmp(lf->filename, koname) == 0)
508 			break;
509 		if (strcmp(lf->filename, filename) == 0)
510 			break;
511 	}
512 	free(koname, M_LINKER);
513 	return (lf);
514 }
515 
516 static linker_file_t
517 linker_find_file_by_id(int fileid)
518 {
519 	linker_file_t lf;
520 
521 	KLD_LOCK_ASSERT();
522 	TAILQ_FOREACH(lf, &linker_files, link)
523 		if (lf->id == fileid && lf->flags & LINKER_FILE_LINKED)
524 			break;
525 	return (lf);
526 }
527 
528 int
529 linker_file_foreach(linker_predicate_t *predicate, void *context)
530 {
531 	linker_file_t lf;
532 	int retval = 0;
533 
534 	KLD_LOCK();
535 	TAILQ_FOREACH(lf, &linker_files, link) {
536 		retval = predicate(lf, context);
537 		if (retval != 0)
538 			break;
539 	}
540 	KLD_UNLOCK();
541 	return (retval);
542 }
543 
544 linker_file_t
545 linker_make_file(const char *pathname, linker_class_t lc)
546 {
547 	linker_file_t lf;
548 	const char *filename;
549 
550 	KLD_LOCK_ASSERT();
551 	filename = linker_basename(pathname);
552 
553 	KLD_DPF(FILE, ("linker_make_file: new file, filename='%s' for pathname='%s'\n", filename, pathname));
554 	lf = (linker_file_t)kobj_create((kobj_class_t)lc, M_LINKER, M_WAITOK);
555 	if (lf == NULL)
556 		return (NULL);
557 	lf->refs = 1;
558 	lf->userrefs = 0;
559 	lf->flags = 0;
560 	lf->filename = linker_strdup(filename);
561 	lf->pathname = linker_strdup(pathname);
562 	LINKER_GET_NEXT_FILE_ID(lf->id);
563 	lf->ndeps = 0;
564 	lf->deps = NULL;
565 	lf->loadcnt = ++loadcnt;
566 	lf->sdt_probes = NULL;
567 	lf->sdt_nprobes = 0;
568 	STAILQ_INIT(&lf->common);
569 	TAILQ_INIT(&lf->modules);
570 	TAILQ_INSERT_TAIL(&linker_files, lf, link);
571 	return (lf);
572 }
573 
574 int
575 linker_file_unload(linker_file_t file, int flags)
576 {
577 	module_t mod, next;
578 	modlist_t ml, nextml;
579 	struct common_symbol *cp;
580 	int error, i;
581 
582 	/* Refuse to unload modules if securelevel raised. */
583 	if (securelevel > 0)
584 		return (EPERM);
585 
586 	KLD_LOCK_ASSERT();
587 	KLD_DPF(FILE, ("linker_file_unload: lf->refs=%d\n", file->refs));
588 
589 	/* Easy case of just dropping a reference. */
590 	if (file->refs > 1) {
591 		file->refs--;
592 		return (0);
593 	}
594 
595 	KLD_DPF(FILE, ("linker_file_unload: file is unloading,"
596 	    " informing modules\n"));
597 
598 	/*
599 	 * Quiesce all the modules to give them a chance to veto the unload.
600 	 */
601 	MOD_SLOCK;
602 	for (mod = TAILQ_FIRST(&file->modules); mod;
603 	     mod = module_getfnext(mod)) {
604 
605 		error = module_quiesce(mod);
606 		if (error != 0 && flags != LINKER_UNLOAD_FORCE) {
607 			KLD_DPF(FILE, ("linker_file_unload: module %s"
608 			    " vetoed unload\n", module_getname(mod)));
609 			/*
610 			 * XXX: Do we need to tell all the quiesced modules
611 			 * that they can resume work now via a new module
612 			 * event?
613 			 */
614 			MOD_SUNLOCK;
615 			return (error);
616 		}
617 	}
618 	MOD_SUNLOCK;
619 
620 	/*
621 	 * Inform any modules associated with this file that they are
622 	 * being be unloaded.
623 	 */
624 	MOD_XLOCK;
625 	for (mod = TAILQ_FIRST(&file->modules); mod; mod = next) {
626 		next = module_getfnext(mod);
627 		MOD_XUNLOCK;
628 
629 		/*
630 		 * Give the module a chance to veto the unload.
631 		 */
632 		if ((error = module_unload(mod)) != 0) {
633 			KLD_DPF(FILE, ("linker_file_unload: module %s"
634 			    " failed unload\n", mod));
635 			return (error);
636 		}
637 		MOD_XLOCK;
638 		module_release(mod);
639 	}
640 	MOD_XUNLOCK;
641 
642 	TAILQ_FOREACH_SAFE(ml, &found_modules, link, nextml) {
643 		if (ml->container == file) {
644 			TAILQ_REMOVE(&found_modules, ml, link);
645 			free(ml, M_LINKER);
646 		}
647 	}
648 
649 	/*
650 	 * Don't try to run SYSUNINITs if we are unloaded due to a
651 	 * link error.
652 	 */
653 	if (file->flags & LINKER_FILE_LINKED) {
654 		file->flags &= ~LINKER_FILE_LINKED;
655 		KLD_UNLOCK();
656 		linker_file_sysuninit(file);
657 		linker_file_unregister_sysctls(file);
658 		KLD_LOCK();
659 	}
660 	TAILQ_REMOVE(&linker_files, file, link);
661 
662 	if (file->deps) {
663 		for (i = 0; i < file->ndeps; i++)
664 			linker_file_unload(file->deps[i], flags);
665 		free(file->deps, M_LINKER);
666 		file->deps = NULL;
667 	}
668 	while ((cp = STAILQ_FIRST(&file->common)) != NULL) {
669 		STAILQ_REMOVE_HEAD(&file->common, link);
670 		free(cp, M_LINKER);
671 	}
672 
673 	LINKER_UNLOAD(file);
674 	if (file->filename) {
675 		free(file->filename, M_LINKER);
676 		file->filename = NULL;
677 	}
678 	if (file->pathname) {
679 		free(file->pathname, M_LINKER);
680 		file->pathname = NULL;
681 	}
682 	kobj_delete((kobj_t) file, M_LINKER);
683 	return (0);
684 }
685 
686 int
687 linker_ctf_get(linker_file_t file, linker_ctf_t *lc)
688 {
689 	return (LINKER_CTF_GET(file, lc));
690 }
691 
692 static int
693 linker_file_add_dependency(linker_file_t file, linker_file_t dep)
694 {
695 	linker_file_t *newdeps;
696 
697 	KLD_LOCK_ASSERT();
698 	newdeps = malloc((file->ndeps + 1) * sizeof(linker_file_t *),
699 	    M_LINKER, M_WAITOK | M_ZERO);
700 	if (newdeps == NULL)
701 		return (ENOMEM);
702 
703 	if (file->deps) {
704 		bcopy(file->deps, newdeps,
705 		    file->ndeps * sizeof(linker_file_t *));
706 		free(file->deps, M_LINKER);
707 	}
708 	file->deps = newdeps;
709 	file->deps[file->ndeps] = dep;
710 	file->ndeps++;
711 	return (0);
712 }
713 
714 /*
715  * Locate a linker set and its contents.  This is a helper function to avoid
716  * linker_if.h exposure elsewhere.  Note: firstp and lastp are really void **.
717  * This function is used in this file so we can avoid having lots of (void **)
718  * casts.
719  */
720 int
721 linker_file_lookup_set(linker_file_t file, const char *name,
722     void *firstp, void *lastp, int *countp)
723 {
724 	int error, locked;
725 
726 	locked = KLD_LOCKED();
727 	if (!locked)
728 		KLD_LOCK();
729 	error = LINKER_LOOKUP_SET(file, name, firstp, lastp, countp);
730 	if (!locked)
731 		KLD_UNLOCK();
732 	return (error);
733 }
734 
735 /*
736  * List all functions in a file.
737  */
738 int
739 linker_file_function_listall(linker_file_t lf,
740     linker_function_nameval_callback_t callback_func, void *arg)
741 {
742 	return (LINKER_EACH_FUNCTION_NAMEVAL(lf, callback_func, arg));
743 }
744 
745 caddr_t
746 linker_file_lookup_symbol(linker_file_t file, const char *name, int deps)
747 {
748 	caddr_t sym;
749 	int locked;
750 
751 	locked = KLD_LOCKED();
752 	if (!locked)
753 		KLD_LOCK();
754 	sym = linker_file_lookup_symbol_internal(file, name, deps);
755 	if (!locked)
756 		KLD_UNLOCK();
757 	return (sym);
758 }
759 
760 static caddr_t
761 linker_file_lookup_symbol_internal(linker_file_t file, const char *name,
762     int deps)
763 {
764 	c_linker_sym_t sym;
765 	linker_symval_t symval;
766 	caddr_t address;
767 	size_t common_size = 0;
768 	int i;
769 
770 	KLD_LOCK_ASSERT();
771 	KLD_DPF(SYM, ("linker_file_lookup_symbol: file=%p, name=%s, deps=%d\n",
772 	    file, name, deps));
773 
774 	if (LINKER_LOOKUP_SYMBOL(file, name, &sym) == 0) {
775 		LINKER_SYMBOL_VALUES(file, sym, &symval);
776 		if (symval.value == 0)
777 			/*
778 			 * For commons, first look them up in the
779 			 * dependencies and only allocate space if not found
780 			 * there.
781 			 */
782 			common_size = symval.size;
783 		else {
784 			KLD_DPF(SYM, ("linker_file_lookup_symbol: symbol"
785 			    ".value=%p\n", symval.value));
786 			return (symval.value);
787 		}
788 	}
789 	if (deps) {
790 		for (i = 0; i < file->ndeps; i++) {
791 			address = linker_file_lookup_symbol_internal(
792 			    file->deps[i], name, 0);
793 			if (address) {
794 				KLD_DPF(SYM, ("linker_file_lookup_symbol:"
795 				    " deps value=%p\n", address));
796 				return (address);
797 			}
798 		}
799 	}
800 	if (common_size > 0) {
801 		/*
802 		 * This is a common symbol which was not found in the
803 		 * dependencies.  We maintain a simple common symbol table in
804 		 * the file object.
805 		 */
806 		struct common_symbol *cp;
807 
808 		STAILQ_FOREACH(cp, &file->common, link) {
809 			if (strcmp(cp->name, name) == 0) {
810 				KLD_DPF(SYM, ("linker_file_lookup_symbol:"
811 				    " old common value=%p\n", cp->address));
812 				return (cp->address);
813 			}
814 		}
815 		/*
816 		 * Round the symbol size up to align.
817 		 */
818 		common_size = (common_size + sizeof(int) - 1) & -sizeof(int);
819 		cp = malloc(sizeof(struct common_symbol)
820 		    + common_size + strlen(name) + 1, M_LINKER,
821 		    M_WAITOK | M_ZERO);
822 		cp->address = (caddr_t)(cp + 1);
823 		cp->name = cp->address + common_size;
824 		strcpy(cp->name, name);
825 		bzero(cp->address, common_size);
826 		STAILQ_INSERT_TAIL(&file->common, cp, link);
827 
828 		KLD_DPF(SYM, ("linker_file_lookup_symbol: new common"
829 		    " value=%p\n", cp->address));
830 		return (cp->address);
831 	}
832 	KLD_DPF(SYM, ("linker_file_lookup_symbol: fail\n"));
833 	return (0);
834 }
835 
836 /*
837  * Both DDB and stack(9) rely on the kernel linker to provide forward and
838  * backward lookup of symbols.  However, DDB and sometimes stack(9) need to
839  * do this in a lockfree manner.  We provide a set of internal helper
840  * routines to perform these operations without locks, and then wrappers that
841  * optionally lock.
842  *
843  * linker_debug_lookup() is ifdef DDB as currently it's only used by DDB.
844  */
845 #ifdef DDB
846 static int
847 linker_debug_lookup(const char *symstr, c_linker_sym_t *sym)
848 {
849 	linker_file_t lf;
850 
851 	TAILQ_FOREACH(lf, &linker_files, link) {
852 		if (LINKER_LOOKUP_SYMBOL(lf, symstr, sym) == 0)
853 			return (0);
854 	}
855 	return (ENOENT);
856 }
857 #endif
858 
859 static int
860 linker_debug_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp)
861 {
862 	linker_file_t lf;
863 	c_linker_sym_t best, es;
864 	u_long diff, bestdiff, off;
865 
866 	best = 0;
867 	off = (uintptr_t)value;
868 	bestdiff = off;
869 	TAILQ_FOREACH(lf, &linker_files, link) {
870 		if (LINKER_SEARCH_SYMBOL(lf, value, &es, &diff) != 0)
871 			continue;
872 		if (es != 0 && diff < bestdiff) {
873 			best = es;
874 			bestdiff = diff;
875 		}
876 		if (bestdiff == 0)
877 			break;
878 	}
879 	if (best) {
880 		*sym = best;
881 		*diffp = bestdiff;
882 		return (0);
883 	} else {
884 		*sym = 0;
885 		*diffp = off;
886 		return (ENOENT);
887 	}
888 }
889 
890 static int
891 linker_debug_symbol_values(c_linker_sym_t sym, linker_symval_t *symval)
892 {
893 	linker_file_t lf;
894 
895 	TAILQ_FOREACH(lf, &linker_files, link) {
896 		if (LINKER_SYMBOL_VALUES(lf, sym, symval) == 0)
897 			return (0);
898 	}
899 	return (ENOENT);
900 }
901 
902 static int
903 linker_debug_search_symbol_name(caddr_t value, char *buf, u_int buflen,
904     long *offset)
905 {
906 	linker_symval_t symval;
907 	c_linker_sym_t sym;
908 	int error;
909 
910 	*offset = 0;
911 	error = linker_debug_search_symbol(value, &sym, offset);
912 	if (error)
913 		return (error);
914 	error = linker_debug_symbol_values(sym, &symval);
915 	if (error)
916 		return (error);
917 	strlcpy(buf, symval.name, buflen);
918 	return (0);
919 }
920 
921 #ifdef DDB
922 /*
923  * DDB Helpers.  DDB has to look across multiple files with their own symbol
924  * tables and string tables.
925  *
926  * Note that we do not obey list locking protocols here.  We really don't need
927  * DDB to hang because somebody's got the lock held.  We'll take the chance
928  * that the files list is inconsistant instead.
929  */
930 int
931 linker_ddb_lookup(const char *symstr, c_linker_sym_t *sym)
932 {
933 
934 	return (linker_debug_lookup(symstr, sym));
935 }
936 
937 int
938 linker_ddb_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp)
939 {
940 
941 	return (linker_debug_search_symbol(value, sym, diffp));
942 }
943 
944 int
945 linker_ddb_symbol_values(c_linker_sym_t sym, linker_symval_t *symval)
946 {
947 
948 	return (linker_debug_symbol_values(sym, symval));
949 }
950 
951 int
952 linker_ddb_search_symbol_name(caddr_t value, char *buf, u_int buflen,
953     long *offset)
954 {
955 
956 	return (linker_debug_search_symbol_name(value, buf, buflen, offset));
957 }
958 #endif
959 
960 /*
961  * stack(9) helper for non-debugging environemnts.  Unlike DDB helpers, we do
962  * obey locking protocols, and offer a significantly less complex interface.
963  */
964 int
965 linker_search_symbol_name(caddr_t value, char *buf, u_int buflen,
966     long *offset)
967 {
968 	int error;
969 
970 	KLD_LOCK();
971 	error = linker_debug_search_symbol_name(value, buf, buflen, offset);
972 	KLD_UNLOCK();
973 	return (error);
974 }
975 
976 /*
977  * Syscalls.
978  */
979 int
980 kern_kldload(struct thread *td, const char *file, int *fileid)
981 {
982 #ifdef HWPMC_HOOKS
983 	struct pmckern_map_in pkm;
984 #endif
985 	const char *kldname, *modname;
986 	linker_file_t lf;
987 	int error;
988 
989 	if ((error = securelevel_gt(td->td_ucred, 0)) != 0)
990 		return (error);
991 
992 	if ((error = priv_check(td, PRIV_KLD_LOAD)) != 0)
993 		return (error);
994 
995 	/*
996 	 * If file does not contain a qualified name or any dot in it
997 	 * (kldname.ko, or kldname.ver.ko) treat it as an interface
998 	 * name.
999 	 */
1000 	if (index(file, '/') || index(file, '.')) {
1001 		kldname = file;
1002 		modname = NULL;
1003 	} else {
1004 		kldname = NULL;
1005 		modname = file;
1006 	}
1007 
1008 	KLD_LOCK();
1009 	error = linker_load_module(kldname, modname, NULL, NULL, &lf);
1010 	if (error)
1011 		goto unlock;
1012 #ifdef HWPMC_HOOKS
1013 	pkm.pm_file = lf->filename;
1014 	pkm.pm_address = (uintptr_t) lf->address;
1015 	PMC_CALL_HOOK(td, PMC_FN_KLD_LOAD, (void *) &pkm);
1016 #endif
1017 	lf->userrefs++;
1018 	if (fileid != NULL)
1019 		*fileid = lf->id;
1020 unlock:
1021 	KLD_UNLOCK();
1022 	return (error);
1023 }
1024 
1025 int
1026 kldload(struct thread *td, struct kldload_args *uap)
1027 {
1028 	char *pathname = NULL;
1029 	int error, fileid;
1030 
1031 	td->td_retval[0] = -1;
1032 
1033 	pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
1034 	error = copyinstr(uap->file, pathname, MAXPATHLEN, NULL);
1035 	if (error == 0) {
1036 		error = kern_kldload(td, pathname, &fileid);
1037 		if (error == 0)
1038 			td->td_retval[0] = fileid;
1039 	}
1040 	free(pathname, M_TEMP);
1041 	return (error);
1042 }
1043 
1044 int
1045 kern_kldunload(struct thread *td, int fileid, int flags)
1046 {
1047 #ifdef HWPMC_HOOKS
1048 	struct pmckern_map_out pkm;
1049 #endif
1050 	linker_file_t lf;
1051 	int error = 0;
1052 
1053 	if ((error = securelevel_gt(td->td_ucred, 0)) != 0)
1054 		return (error);
1055 
1056 	if ((error = priv_check(td, PRIV_KLD_UNLOAD)) != 0)
1057 		return (error);
1058 
1059 	KLD_LOCK();
1060 	lf = linker_find_file_by_id(fileid);
1061 	if (lf) {
1062 		KLD_DPF(FILE, ("kldunload: lf->userrefs=%d\n", lf->userrefs));
1063 
1064 		/* Check if there are DTrace probes enabled on this file. */
1065 		if (lf->nenabled > 0) {
1066 			printf("kldunload: attempt to unload file that has"
1067 			    " DTrace probes enabled\n");
1068 			error = EBUSY;
1069 		} else if (lf->userrefs == 0) {
1070 			/*
1071 			 * XXX: maybe LINKER_UNLOAD_FORCE should override ?
1072 			 */
1073 			printf("kldunload: attempt to unload file that was"
1074 			    " loaded by the kernel\n");
1075 			error = EBUSY;
1076 		} else {
1077 #ifdef HWPMC_HOOKS
1078 			/* Save data needed by hwpmc(4) before unloading. */
1079 			pkm.pm_address = (uintptr_t) lf->address;
1080 			pkm.pm_size = lf->size;
1081 #endif
1082 			lf->userrefs--;
1083 			error = linker_file_unload(lf, flags);
1084 			if (error)
1085 				lf->userrefs++;
1086 		}
1087 	} else
1088 		error = ENOENT;
1089 
1090 #ifdef HWPMC_HOOKS
1091 	if (error == 0)
1092 		PMC_CALL_HOOK(td, PMC_FN_KLD_UNLOAD, (void *) &pkm);
1093 #endif
1094 	KLD_UNLOCK();
1095 	return (error);
1096 }
1097 
1098 int
1099 kldunload(struct thread *td, struct kldunload_args *uap)
1100 {
1101 
1102 	return (kern_kldunload(td, uap->fileid, LINKER_UNLOAD_NORMAL));
1103 }
1104 
1105 int
1106 kldunloadf(struct thread *td, struct kldunloadf_args *uap)
1107 {
1108 
1109 	if (uap->flags != LINKER_UNLOAD_NORMAL &&
1110 	    uap->flags != LINKER_UNLOAD_FORCE)
1111 		return (EINVAL);
1112 	return (kern_kldunload(td, uap->fileid, uap->flags));
1113 }
1114 
1115 int
1116 kldfind(struct thread *td, struct kldfind_args *uap)
1117 {
1118 	char *pathname;
1119 	const char *filename;
1120 	linker_file_t lf;
1121 	int error;
1122 
1123 #ifdef MAC
1124 	error = mac_kld_check_stat(td->td_ucred);
1125 	if (error)
1126 		return (error);
1127 #endif
1128 
1129 	td->td_retval[0] = -1;
1130 
1131 	pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
1132 	if ((error = copyinstr(uap->file, pathname, MAXPATHLEN, NULL)) != 0)
1133 		goto out;
1134 
1135 	filename = linker_basename(pathname);
1136 	KLD_LOCK();
1137 	lf = linker_find_file_by_name(filename);
1138 	if (lf)
1139 		td->td_retval[0] = lf->id;
1140 	else
1141 		error = ENOENT;
1142 	KLD_UNLOCK();
1143 out:
1144 	free(pathname, M_TEMP);
1145 	return (error);
1146 }
1147 
1148 int
1149 kldnext(struct thread *td, struct kldnext_args *uap)
1150 {
1151 	linker_file_t lf;
1152 	int error = 0;
1153 
1154 #ifdef MAC
1155 	error = mac_kld_check_stat(td->td_ucred);
1156 	if (error)
1157 		return (error);
1158 #endif
1159 
1160 	KLD_LOCK();
1161 	if (uap->fileid == 0)
1162 		lf = TAILQ_FIRST(&linker_files);
1163 	else {
1164 		lf = linker_find_file_by_id(uap->fileid);
1165 		if (lf == NULL) {
1166 			error = ENOENT;
1167 			goto out;
1168 		}
1169 		lf = TAILQ_NEXT(lf, link);
1170 	}
1171 
1172 	/* Skip partially loaded files. */
1173 	while (lf != NULL && !(lf->flags & LINKER_FILE_LINKED))
1174 		lf = TAILQ_NEXT(lf, link);
1175 
1176 	if (lf)
1177 		td->td_retval[0] = lf->id;
1178 	else
1179 		td->td_retval[0] = 0;
1180 out:
1181 	KLD_UNLOCK();
1182 	return (error);
1183 }
1184 
1185 int
1186 kldstat(struct thread *td, struct kldstat_args *uap)
1187 {
1188 	struct kld_file_stat stat;
1189 	linker_file_t lf;
1190 	int error, namelen, version, version_num;
1191 
1192 	/*
1193 	 * Check the version of the user's structure.
1194 	 */
1195 	if ((error = copyin(&uap->stat->version, &version, sizeof(version))) != 0)
1196 		return (error);
1197 	if (version == sizeof(struct kld_file_stat_1))
1198 		version_num = 1;
1199 	else if (version == sizeof(struct kld_file_stat))
1200 		version_num = 2;
1201 	else
1202 		return (EINVAL);
1203 
1204 #ifdef MAC
1205 	error = mac_kld_check_stat(td->td_ucred);
1206 	if (error)
1207 		return (error);
1208 #endif
1209 
1210 	KLD_LOCK();
1211 	lf = linker_find_file_by_id(uap->fileid);
1212 	if (lf == NULL) {
1213 		KLD_UNLOCK();
1214 		return (ENOENT);
1215 	}
1216 
1217 	/* Version 1 fields: */
1218 	namelen = strlen(lf->filename) + 1;
1219 	if (namelen > MAXPATHLEN)
1220 		namelen = MAXPATHLEN;
1221 	bcopy(lf->filename, &stat.name[0], namelen);
1222 	stat.refs = lf->refs;
1223 	stat.id = lf->id;
1224 	stat.address = lf->address;
1225 	stat.size = lf->size;
1226 	if (version_num > 1) {
1227 		/* Version 2 fields: */
1228 		namelen = strlen(lf->pathname) + 1;
1229 		if (namelen > MAXPATHLEN)
1230 			namelen = MAXPATHLEN;
1231 		bcopy(lf->pathname, &stat.pathname[0], namelen);
1232 	}
1233 	KLD_UNLOCK();
1234 
1235 	td->td_retval[0] = 0;
1236 
1237 	return (copyout(&stat, uap->stat, version));
1238 }
1239 
1240 int
1241 kldfirstmod(struct thread *td, struct kldfirstmod_args *uap)
1242 {
1243 	linker_file_t lf;
1244 	module_t mp;
1245 	int error = 0;
1246 
1247 #ifdef MAC
1248 	error = mac_kld_check_stat(td->td_ucred);
1249 	if (error)
1250 		return (error);
1251 #endif
1252 
1253 	KLD_LOCK();
1254 	lf = linker_find_file_by_id(uap->fileid);
1255 	if (lf) {
1256 		MOD_SLOCK;
1257 		mp = TAILQ_FIRST(&lf->modules);
1258 		if (mp != NULL)
1259 			td->td_retval[0] = module_getid(mp);
1260 		else
1261 			td->td_retval[0] = 0;
1262 		MOD_SUNLOCK;
1263 	} else
1264 		error = ENOENT;
1265 	KLD_UNLOCK();
1266 	return (error);
1267 }
1268 
1269 int
1270 kldsym(struct thread *td, struct kldsym_args *uap)
1271 {
1272 	char *symstr = NULL;
1273 	c_linker_sym_t sym;
1274 	linker_symval_t symval;
1275 	linker_file_t lf;
1276 	struct kld_sym_lookup lookup;
1277 	int error = 0;
1278 
1279 #ifdef MAC
1280 	error = mac_kld_check_stat(td->td_ucred);
1281 	if (error)
1282 		return (error);
1283 #endif
1284 
1285 	if ((error = copyin(uap->data, &lookup, sizeof(lookup))) != 0)
1286 		return (error);
1287 	if (lookup.version != sizeof(lookup) ||
1288 	    uap->cmd != KLDSYM_LOOKUP)
1289 		return (EINVAL);
1290 	symstr = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
1291 	if ((error = copyinstr(lookup.symname, symstr, MAXPATHLEN, NULL)) != 0)
1292 		goto out;
1293 	KLD_LOCK();
1294 	if (uap->fileid != 0) {
1295 		lf = linker_find_file_by_id(uap->fileid);
1296 		if (lf == NULL)
1297 			error = ENOENT;
1298 		else if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 &&
1299 		    LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) {
1300 			lookup.symvalue = (uintptr_t) symval.value;
1301 			lookup.symsize = symval.size;
1302 			error = copyout(&lookup, uap->data, sizeof(lookup));
1303 		} else
1304 			error = ENOENT;
1305 	} else {
1306 		TAILQ_FOREACH(lf, &linker_files, link) {
1307 			if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 &&
1308 			    LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) {
1309 				lookup.symvalue = (uintptr_t)symval.value;
1310 				lookup.symsize = symval.size;
1311 				error = copyout(&lookup, uap->data,
1312 				    sizeof(lookup));
1313 				break;
1314 			}
1315 		}
1316 #ifndef VIMAGE_GLOBALS
1317 		/*
1318 		 * If the symbol is not found in global namespace,
1319 		 * try to look it up in the current vimage namespace.
1320 		 */
1321 		if (lf == NULL) {
1322 			CURVNET_SET(TD_TO_VNET(td));
1323 			error = vi_symlookup(&lookup, symstr);
1324 			CURVNET_RESTORE();
1325 			if (error == 0)
1326 				error = copyout(&lookup, uap->data,
1327 						sizeof(lookup));
1328 		}
1329 #else
1330 		if (lf == NULL)
1331 			error = ENOENT;
1332 #endif
1333 	}
1334 	KLD_UNLOCK();
1335 out:
1336 	free(symstr, M_TEMP);
1337 	return (error);
1338 }
1339 
1340 /*
1341  * Preloaded module support
1342  */
1343 
1344 static modlist_t
1345 modlist_lookup(const char *name, int ver)
1346 {
1347 	modlist_t mod;
1348 
1349 	TAILQ_FOREACH(mod, &found_modules, link) {
1350 		if (strcmp(mod->name, name) == 0 &&
1351 		    (ver == 0 || mod->version == ver))
1352 			return (mod);
1353 	}
1354 	return (NULL);
1355 }
1356 
1357 static modlist_t
1358 modlist_lookup2(const char *name, struct mod_depend *verinfo)
1359 {
1360 	modlist_t mod, bestmod;
1361 	int ver;
1362 
1363 	if (verinfo == NULL)
1364 		return (modlist_lookup(name, 0));
1365 	bestmod = NULL;
1366 	TAILQ_FOREACH(mod, &found_modules, link) {
1367 		if (strcmp(mod->name, name) != 0)
1368 			continue;
1369 		ver = mod->version;
1370 		if (ver == verinfo->md_ver_preferred)
1371 			return (mod);
1372 		if (ver >= verinfo->md_ver_minimum &&
1373 		    ver <= verinfo->md_ver_maximum &&
1374 		    (bestmod == NULL || ver > bestmod->version))
1375 			bestmod = mod;
1376 	}
1377 	return (bestmod);
1378 }
1379 
1380 static modlist_t
1381 modlist_newmodule(const char *modname, int version, linker_file_t container)
1382 {
1383 	modlist_t mod;
1384 
1385 	mod = malloc(sizeof(struct modlist), M_LINKER, M_NOWAIT | M_ZERO);
1386 	if (mod == NULL)
1387 		panic("no memory for module list");
1388 	mod->container = container;
1389 	mod->name = modname;
1390 	mod->version = version;
1391 	TAILQ_INSERT_TAIL(&found_modules, mod, link);
1392 	return (mod);
1393 }
1394 
1395 static void
1396 linker_addmodules(linker_file_t lf, struct mod_metadata **start,
1397     struct mod_metadata **stop, int preload)
1398 {
1399 	struct mod_metadata *mp, **mdp;
1400 	const char *modname;
1401 	int ver;
1402 
1403 	for (mdp = start; mdp < stop; mdp++) {
1404 		mp = *mdp;
1405 		if (mp->md_type != MDT_VERSION)
1406 			continue;
1407 		modname = mp->md_cval;
1408 		ver = ((struct mod_version *)mp->md_data)->mv_version;
1409 		if (modlist_lookup(modname, ver) != NULL) {
1410 			printf("module %s already present!\n", modname);
1411 			/* XXX what can we do? this is a build error. :-( */
1412 			continue;
1413 		}
1414 		modlist_newmodule(modname, ver, lf);
1415 	}
1416 }
1417 
1418 static void
1419 linker_preload(void *arg)
1420 {
1421 	caddr_t modptr;
1422 	const char *modname, *nmodname;
1423 	char *modtype;
1424 	linker_file_t lf, nlf;
1425 	linker_class_t lc;
1426 	int error;
1427 	linker_file_list_t loaded_files;
1428 	linker_file_list_t depended_files;
1429 	struct mod_metadata *mp, *nmp;
1430 	struct mod_metadata **start, **stop, **mdp, **nmdp;
1431 	struct mod_depend *verinfo;
1432 	int nver;
1433 	int resolves;
1434 	modlist_t mod;
1435 	struct sysinit **si_start, **si_stop;
1436 
1437 	TAILQ_INIT(&loaded_files);
1438 	TAILQ_INIT(&depended_files);
1439 	TAILQ_INIT(&found_modules);
1440 	error = 0;
1441 
1442 	modptr = NULL;
1443 	while ((modptr = preload_search_next_name(modptr)) != NULL) {
1444 		modname = (char *)preload_search_info(modptr, MODINFO_NAME);
1445 		modtype = (char *)preload_search_info(modptr, MODINFO_TYPE);
1446 		if (modname == NULL) {
1447 			printf("Preloaded module at %p does not have a"
1448 			    " name!\n", modptr);
1449 			continue;
1450 		}
1451 		if (modtype == NULL) {
1452 			printf("Preloaded module at %p does not have a type!\n",
1453 			    modptr);
1454 			continue;
1455 		}
1456 		if (bootverbose)
1457 			printf("Preloaded %s \"%s\" at %p.\n", modtype, modname,
1458 			    modptr);
1459 		lf = NULL;
1460 		TAILQ_FOREACH(lc, &classes, link) {
1461 			error = LINKER_LINK_PRELOAD(lc, modname, &lf);
1462 			if (!error)
1463 				break;
1464 			lf = NULL;
1465 		}
1466 		if (lf)
1467 			TAILQ_INSERT_TAIL(&loaded_files, lf, loaded);
1468 	}
1469 
1470 	/*
1471 	 * First get a list of stuff in the kernel.
1472 	 */
1473 	if (linker_file_lookup_set(linker_kernel_file, MDT_SETNAME, &start,
1474 	    &stop, NULL) == 0)
1475 		linker_addmodules(linker_kernel_file, start, stop, 1);
1476 
1477 	/*
1478 	 * This is a once-off kinky bubble sort to resolve relocation
1479 	 * dependency requirements.
1480 	 */
1481 restart:
1482 	TAILQ_FOREACH(lf, &loaded_files, loaded) {
1483 		error = linker_file_lookup_set(lf, MDT_SETNAME, &start,
1484 		    &stop, NULL);
1485 		/*
1486 		 * First, look to see if we would successfully link with this
1487 		 * stuff.
1488 		 */
1489 		resolves = 1;	/* unless we know otherwise */
1490 		if (!error) {
1491 			for (mdp = start; mdp < stop; mdp++) {
1492 				mp = *mdp;
1493 				if (mp->md_type != MDT_DEPEND)
1494 					continue;
1495 				modname = mp->md_cval;
1496 				verinfo = mp->md_data;
1497 				for (nmdp = start; nmdp < stop; nmdp++) {
1498 					nmp = *nmdp;
1499 					if (nmp->md_type != MDT_VERSION)
1500 						continue;
1501 					nmodname = nmp->md_cval;
1502 					if (strcmp(modname, nmodname) == 0)
1503 						break;
1504 				}
1505 				if (nmdp < stop)   /* it's a self reference */
1506 					continue;
1507 
1508 				/*
1509 				 * ok, the module isn't here yet, we
1510 				 * are not finished
1511 				 */
1512 				if (modlist_lookup2(modname, verinfo) == NULL)
1513 					resolves = 0;
1514 			}
1515 		}
1516 		/*
1517 		 * OK, if we found our modules, we can link.  So, "provide"
1518 		 * the modules inside and add it to the end of the link order
1519 		 * list.
1520 		 */
1521 		if (resolves) {
1522 			if (!error) {
1523 				for (mdp = start; mdp < stop; mdp++) {
1524 					mp = *mdp;
1525 					if (mp->md_type != MDT_VERSION)
1526 						continue;
1527 					modname = mp->md_cval;
1528 					nver = ((struct mod_version *)
1529 					    mp->md_data)->mv_version;
1530 					if (modlist_lookup(modname,
1531 					    nver) != NULL) {
1532 						printf("module %s already"
1533 						    " present!\n", modname);
1534 						TAILQ_REMOVE(&loaded_files,
1535 						    lf, loaded);
1536 						linker_file_unload(lf,
1537 						    LINKER_UNLOAD_FORCE);
1538 						/* we changed tailq next ptr */
1539 						goto restart;
1540 					}
1541 					modlist_newmodule(modname, nver, lf);
1542 				}
1543 			}
1544 			TAILQ_REMOVE(&loaded_files, lf, loaded);
1545 			TAILQ_INSERT_TAIL(&depended_files, lf, loaded);
1546 			/*
1547 			 * Since we provided modules, we need to restart the
1548 			 * sort so that the previous files that depend on us
1549 			 * have a chance. Also, we've busted the tailq next
1550 			 * pointer with the REMOVE.
1551 			 */
1552 			goto restart;
1553 		}
1554 	}
1555 
1556 	/*
1557 	 * At this point, we check to see what could not be resolved..
1558 	 */
1559 	while ((lf = TAILQ_FIRST(&loaded_files)) != NULL) {
1560 		TAILQ_REMOVE(&loaded_files, lf, loaded);
1561 		printf("KLD file %s is missing dependencies\n", lf->filename);
1562 		linker_file_unload(lf, LINKER_UNLOAD_FORCE);
1563 	}
1564 
1565 	/*
1566 	 * We made it. Finish off the linking in the order we determined.
1567 	 */
1568 	TAILQ_FOREACH_SAFE(lf, &depended_files, loaded, nlf) {
1569 		if (linker_kernel_file) {
1570 			linker_kernel_file->refs++;
1571 			error = linker_file_add_dependency(lf,
1572 			    linker_kernel_file);
1573 			if (error)
1574 				panic("cannot add dependency");
1575 		}
1576 		lf->userrefs++;	/* so we can (try to) kldunload it */
1577 		error = linker_file_lookup_set(lf, MDT_SETNAME, &start,
1578 		    &stop, NULL);
1579 		if (!error) {
1580 			for (mdp = start; mdp < stop; mdp++) {
1581 				mp = *mdp;
1582 				if (mp->md_type != MDT_DEPEND)
1583 					continue;
1584 				modname = mp->md_cval;
1585 				verinfo = mp->md_data;
1586 				mod = modlist_lookup2(modname, verinfo);
1587 				/* Don't count self-dependencies */
1588 				if (lf == mod->container)
1589 					continue;
1590 				mod->container->refs++;
1591 				error = linker_file_add_dependency(lf,
1592 				    mod->container);
1593 				if (error)
1594 					panic("cannot add dependency");
1595 			}
1596 		}
1597 		/*
1598 		 * Now do relocation etc using the symbol search paths
1599 		 * established by the dependencies
1600 		 */
1601 		error = LINKER_LINK_PRELOAD_FINISH(lf);
1602 		if (error) {
1603 			TAILQ_REMOVE(&depended_files, lf, loaded);
1604 			printf("KLD file %s - could not finalize loading\n",
1605 			    lf->filename);
1606 			linker_file_unload(lf, LINKER_UNLOAD_FORCE);
1607 			continue;
1608 		}
1609 		linker_file_register_modules(lf);
1610 		if (linker_file_lookup_set(lf, "sysinit_set", &si_start,
1611 		    &si_stop, NULL) == 0)
1612 			sysinit_add(si_start, si_stop);
1613 		linker_file_register_sysctls(lf);
1614 		lf->flags |= LINKER_FILE_LINKED;
1615 	}
1616 	/* woohoo! we made it! */
1617 }
1618 
1619 SYSINIT(preload, SI_SUB_KLD, SI_ORDER_MIDDLE, linker_preload, 0);
1620 
1621 /*
1622  * Search for a not-loaded module by name.
1623  *
1624  * Modules may be found in the following locations:
1625  *
1626  * - preloaded (result is just the module name) - on disk (result is full path
1627  * to module)
1628  *
1629  * If the module name is qualified in any way (contains path, etc.) the we
1630  * simply return a copy of it.
1631  *
1632  * The search path can be manipulated via sysctl.  Note that we use the ';'
1633  * character as a separator to be consistent with the bootloader.
1634  */
1635 
1636 static char linker_hintfile[] = "linker.hints";
1637 static char linker_path[MAXPATHLEN] = "/boot/kernel;/boot/modules";
1638 
1639 SYSCTL_STRING(_kern, OID_AUTO, module_path, CTLFLAG_RW, linker_path,
1640     sizeof(linker_path), "module load search path");
1641 
1642 TUNABLE_STR("module_path", linker_path, sizeof(linker_path));
1643 
1644 static char *linker_ext_list[] = {
1645 	"",
1646 	".ko",
1647 	NULL
1648 };
1649 
1650 /*
1651  * Check if file actually exists either with or without extension listed in
1652  * the linker_ext_list. (probably should be generic for the rest of the
1653  * kernel)
1654  */
1655 static char *
1656 linker_lookup_file(const char *path, int pathlen, const char *name,
1657     int namelen, struct vattr *vap)
1658 {
1659 	struct nameidata nd;
1660 	struct thread *td = curthread;	/* XXX */
1661 	char *result, **cpp, *sep;
1662 	int error, len, extlen, reclen, flags, vfslocked;
1663 	enum vtype type;
1664 
1665 	extlen = 0;
1666 	for (cpp = linker_ext_list; *cpp; cpp++) {
1667 		len = strlen(*cpp);
1668 		if (len > extlen)
1669 			extlen = len;
1670 	}
1671 	extlen++;		/* trailing '\0' */
1672 	sep = (path[pathlen - 1] != '/') ? "/" : "";
1673 
1674 	reclen = pathlen + strlen(sep) + namelen + extlen + 1;
1675 	result = malloc(reclen, M_LINKER, M_WAITOK);
1676 	for (cpp = linker_ext_list; *cpp; cpp++) {
1677 		snprintf(result, reclen, "%.*s%s%.*s%s", pathlen, path, sep,
1678 		    namelen, name, *cpp);
1679 		/*
1680 		 * Attempt to open the file, and return the path if
1681 		 * we succeed and it's a regular file.
1682 		 */
1683 		NDINIT(&nd, LOOKUP, FOLLOW | MPSAFE, UIO_SYSSPACE, result, td);
1684 		flags = FREAD;
1685 		error = vn_open(&nd, &flags, 0, NULL);
1686 		if (error == 0) {
1687 			vfslocked = NDHASGIANT(&nd);
1688 			NDFREE(&nd, NDF_ONLY_PNBUF);
1689 			type = nd.ni_vp->v_type;
1690 			if (vap)
1691 				VOP_GETATTR(nd.ni_vp, vap, td->td_ucred);
1692 			VOP_UNLOCK(nd.ni_vp, 0);
1693 			vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
1694 			VFS_UNLOCK_GIANT(vfslocked);
1695 			if (type == VREG)
1696 				return (result);
1697 		}
1698 	}
1699 	free(result, M_LINKER);
1700 	return (NULL);
1701 }
1702 
1703 #define	INT_ALIGN(base, ptr)	ptr =					\
1704 	(base) + (((ptr) - (base) + sizeof(int) - 1) & ~(sizeof(int) - 1))
1705 
1706 /*
1707  * Lookup KLD which contains requested module in the "linker.hints" file. If
1708  * version specification is available, then try to find the best KLD.
1709  * Otherwise just find the latest one.
1710  */
1711 static char *
1712 linker_hints_lookup(const char *path, int pathlen, const char *modname,
1713     int modnamelen, struct mod_depend *verinfo)
1714 {
1715 	struct thread *td = curthread;	/* XXX */
1716 	struct ucred *cred = td ? td->td_ucred : NULL;
1717 	struct nameidata nd;
1718 	struct vattr vattr, mattr;
1719 	u_char *hints = NULL;
1720 	u_char *cp, *recptr, *bufend, *result, *best, *pathbuf, *sep;
1721 	int error, ival, bestver, *intp, reclen, found, flags, clen, blen;
1722 	int vfslocked = 0;
1723 
1724 	result = NULL;
1725 	bestver = found = 0;
1726 
1727 	sep = (path[pathlen - 1] != '/') ? "/" : "";
1728 	reclen = imax(modnamelen, strlen(linker_hintfile)) + pathlen +
1729 	    strlen(sep) + 1;
1730 	pathbuf = malloc(reclen, M_LINKER, M_WAITOK);
1731 	snprintf(pathbuf, reclen, "%.*s%s%s", pathlen, path, sep,
1732 	    linker_hintfile);
1733 
1734 	NDINIT(&nd, LOOKUP, NOFOLLOW | MPSAFE, UIO_SYSSPACE, pathbuf, td);
1735 	flags = FREAD;
1736 	error = vn_open(&nd, &flags, 0, NULL);
1737 	if (error)
1738 		goto bad;
1739 	vfslocked = NDHASGIANT(&nd);
1740 	NDFREE(&nd, NDF_ONLY_PNBUF);
1741 	if (nd.ni_vp->v_type != VREG)
1742 		goto bad;
1743 	best = cp = NULL;
1744 	error = VOP_GETATTR(nd.ni_vp, &vattr, cred);
1745 	if (error)
1746 		goto bad;
1747 	/*
1748 	 * XXX: we need to limit this number to some reasonable value
1749 	 */
1750 	if (vattr.va_size > 100 * 1024) {
1751 		printf("hints file too large %ld\n", (long)vattr.va_size);
1752 		goto bad;
1753 	}
1754 	hints = malloc(vattr.va_size, M_TEMP, M_WAITOK);
1755 	if (hints == NULL)
1756 		goto bad;
1757 	error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)hints, vattr.va_size, 0,
1758 	    UIO_SYSSPACE, IO_NODELOCKED, cred, NOCRED, &reclen, td);
1759 	if (error)
1760 		goto bad;
1761 	VOP_UNLOCK(nd.ni_vp, 0);
1762 	vn_close(nd.ni_vp, FREAD, cred, td);
1763 	VFS_UNLOCK_GIANT(vfslocked);
1764 	nd.ni_vp = NULL;
1765 	if (reclen != 0) {
1766 		printf("can't read %d\n", reclen);
1767 		goto bad;
1768 	}
1769 	intp = (int *)hints;
1770 	ival = *intp++;
1771 	if (ival != LINKER_HINTS_VERSION) {
1772 		printf("hints file version mismatch %d\n", ival);
1773 		goto bad;
1774 	}
1775 	bufend = hints + vattr.va_size;
1776 	recptr = (u_char *)intp;
1777 	clen = blen = 0;
1778 	while (recptr < bufend && !found) {
1779 		intp = (int *)recptr;
1780 		reclen = *intp++;
1781 		ival = *intp++;
1782 		cp = (char *)intp;
1783 		switch (ival) {
1784 		case MDT_VERSION:
1785 			clen = *cp++;
1786 			if (clen != modnamelen || bcmp(cp, modname, clen) != 0)
1787 				break;
1788 			cp += clen;
1789 			INT_ALIGN(hints, cp);
1790 			ival = *(int *)cp;
1791 			cp += sizeof(int);
1792 			clen = *cp++;
1793 			if (verinfo == NULL ||
1794 			    ival == verinfo->md_ver_preferred) {
1795 				found = 1;
1796 				break;
1797 			}
1798 			if (ival >= verinfo->md_ver_minimum &&
1799 			    ival <= verinfo->md_ver_maximum &&
1800 			    ival > bestver) {
1801 				bestver = ival;
1802 				best = cp;
1803 				blen = clen;
1804 			}
1805 			break;
1806 		default:
1807 			break;
1808 		}
1809 		recptr += reclen + sizeof(int);
1810 	}
1811 	/*
1812 	 * Finally check if KLD is in the place
1813 	 */
1814 	if (found)
1815 		result = linker_lookup_file(path, pathlen, cp, clen, &mattr);
1816 	else if (best)
1817 		result = linker_lookup_file(path, pathlen, best, blen, &mattr);
1818 
1819 	/*
1820 	 * KLD is newer than hints file. What we should do now?
1821 	 */
1822 	if (result && timespeccmp(&mattr.va_mtime, &vattr.va_mtime, >))
1823 		printf("warning: KLD '%s' is newer than the linker.hints"
1824 		    " file\n", result);
1825 bad:
1826 	free(pathbuf, M_LINKER);
1827 	if (hints)
1828 		free(hints, M_TEMP);
1829 	if (nd.ni_vp != NULL) {
1830 		VOP_UNLOCK(nd.ni_vp, 0);
1831 		vn_close(nd.ni_vp, FREAD, cred, td);
1832 		VFS_UNLOCK_GIANT(vfslocked);
1833 	}
1834 	/*
1835 	 * If nothing found or hints is absent - fallback to the old
1836 	 * way by using "kldname[.ko]" as module name.
1837 	 */
1838 	if (!found && !bestver && result == NULL)
1839 		result = linker_lookup_file(path, pathlen, modname,
1840 		    modnamelen, NULL);
1841 	return (result);
1842 }
1843 
1844 /*
1845  * Lookup KLD which contains requested module in the all directories.
1846  */
1847 static char *
1848 linker_search_module(const char *modname, int modnamelen,
1849     struct mod_depend *verinfo)
1850 {
1851 	char *cp, *ep, *result;
1852 
1853 	/*
1854 	 * traverse the linker path
1855 	 */
1856 	for (cp = linker_path; *cp; cp = ep + 1) {
1857 		/* find the end of this component */
1858 		for (ep = cp; (*ep != 0) && (*ep != ';'); ep++);
1859 		result = linker_hints_lookup(cp, ep - cp, modname,
1860 		    modnamelen, verinfo);
1861 		if (result != NULL)
1862 			return (result);
1863 		if (*ep == 0)
1864 			break;
1865 	}
1866 	return (NULL);
1867 }
1868 
1869 /*
1870  * Search for module in all directories listed in the linker_path.
1871  */
1872 static char *
1873 linker_search_kld(const char *name)
1874 {
1875 	char *cp, *ep, *result;
1876 	int len;
1877 
1878 	/* qualified at all? */
1879 	if (index(name, '/'))
1880 		return (linker_strdup(name));
1881 
1882 	/* traverse the linker path */
1883 	len = strlen(name);
1884 	for (ep = linker_path; *ep; ep++) {
1885 		cp = ep;
1886 		/* find the end of this component */
1887 		for (; *ep != 0 && *ep != ';'; ep++);
1888 		result = linker_lookup_file(cp, ep - cp, name, len, NULL);
1889 		if (result != NULL)
1890 			return (result);
1891 	}
1892 	return (NULL);
1893 }
1894 
1895 static const char *
1896 linker_basename(const char *path)
1897 {
1898 	const char *filename;
1899 
1900 	filename = rindex(path, '/');
1901 	if (filename == NULL)
1902 		return path;
1903 	if (filename[1])
1904 		filename++;
1905 	return (filename);
1906 }
1907 
1908 #ifdef HWPMC_HOOKS
1909 
1910 struct hwpmc_context {
1911 	int	nobjects;
1912 	int	nmappings;
1913 	struct pmckern_map_in *kobase;
1914 };
1915 
1916 static int
1917 linker_hwpmc_list_object(linker_file_t lf, void *arg)
1918 {
1919 	struct hwpmc_context *hc;
1920 
1921 	hc = arg;
1922 
1923 	/* If we run out of mappings, fail. */
1924 	if (hc->nobjects >= hc->nmappings)
1925 		return (1);
1926 
1927 	/* Save the info for this linker file. */
1928 	hc->kobase[hc->nobjects].pm_file = lf->filename;
1929 	hc->kobase[hc->nobjects].pm_address = (uintptr_t)lf->address;
1930 	hc->nobjects++;
1931 	return (0);
1932 }
1933 
1934 /*
1935  * Inform hwpmc about the set of kernel modules currently loaded.
1936  */
1937 void *
1938 linker_hwpmc_list_objects(void)
1939 {
1940 	struct hwpmc_context hc;
1941 
1942 	hc.nmappings = 15;	/* a reasonable default */
1943 
1944  retry:
1945 	/* allocate nmappings+1 entries */
1946 	hc.kobase = malloc((hc.nmappings + 1) * sizeof(struct pmckern_map_in),
1947 	    M_LINKER, M_WAITOK | M_ZERO);
1948 
1949 	hc.nobjects = 0;
1950 	if (linker_file_foreach(linker_hwpmc_list_object, &hc) != 0) {
1951 		hc.nmappings = hc.nobjects;
1952 		free(hc.kobase, M_LINKER);
1953 		goto retry;
1954 	}
1955 
1956 	KASSERT(hc.nobjects > 0, ("linker_hpwmc_list_objects: no kernel "
1957 		"objects?"));
1958 
1959 	/* The last entry of the malloced area comprises of all zeros. */
1960 	KASSERT(hc.kobase[hc.nobjects].pm_file == NULL,
1961 	    ("linker_hwpmc_list_objects: last object not NULL"));
1962 
1963 	return ((void *)hc.kobase);
1964 }
1965 #endif
1966 
1967 /*
1968  * Find a file which contains given module and load it, if "parent" is not
1969  * NULL, register a reference to it.
1970  */
1971 static int
1972 linker_load_module(const char *kldname, const char *modname,
1973     struct linker_file *parent, struct mod_depend *verinfo,
1974     struct linker_file **lfpp)
1975 {
1976 	linker_file_t lfdep;
1977 	const char *filename;
1978 	char *pathname;
1979 	int error;
1980 
1981 	KLD_LOCK_ASSERT();
1982 	if (modname == NULL) {
1983 		/*
1984  		 * We have to load KLD
1985  		 */
1986 		KASSERT(verinfo == NULL, ("linker_load_module: verinfo"
1987 		    " is not NULL"));
1988 		pathname = linker_search_kld(kldname);
1989 	} else {
1990 		if (modlist_lookup2(modname, verinfo) != NULL)
1991 			return (EEXIST);
1992 		if (kldname != NULL)
1993 			pathname = linker_strdup(kldname);
1994 		else if (rootvnode == NULL)
1995 			pathname = NULL;
1996 		else
1997 			/*
1998 			 * Need to find a KLD with required module
1999 			 */
2000 			pathname = linker_search_module(modname,
2001 			    strlen(modname), verinfo);
2002 	}
2003 	if (pathname == NULL)
2004 		return (ENOENT);
2005 
2006 	/*
2007 	 * Can't load more than one file with the same basename XXX:
2008 	 * Actually it should be possible to have multiple KLDs with
2009 	 * the same basename but different path because they can
2010 	 * provide different versions of the same modules.
2011 	 */
2012 	filename = linker_basename(pathname);
2013 	if (linker_find_file_by_name(filename))
2014 		error = EEXIST;
2015 	else do {
2016 		error = linker_load_file(pathname, &lfdep);
2017 		if (error)
2018 			break;
2019 		if (modname && verinfo &&
2020 		    modlist_lookup2(modname, verinfo) == NULL) {
2021 			linker_file_unload(lfdep, LINKER_UNLOAD_FORCE);
2022 			error = ENOENT;
2023 			break;
2024 		}
2025 		if (parent) {
2026 			error = linker_file_add_dependency(parent, lfdep);
2027 			if (error)
2028 				break;
2029 		}
2030 		if (lfpp)
2031 			*lfpp = lfdep;
2032 	} while (0);
2033 	free(pathname, M_LINKER);
2034 	return (error);
2035 }
2036 
2037 /*
2038  * This routine is responsible for finding dependencies of userland initiated
2039  * kldload(2)'s of files.
2040  */
2041 int
2042 linker_load_dependencies(linker_file_t lf)
2043 {
2044 	linker_file_t lfdep;
2045 	struct mod_metadata **start, **stop, **mdp, **nmdp;
2046 	struct mod_metadata *mp, *nmp;
2047 	struct mod_depend *verinfo;
2048 	modlist_t mod;
2049 	const char *modname, *nmodname;
2050 	int ver, error = 0, count;
2051 
2052 	/*
2053 	 * All files are dependant on /kernel.
2054 	 */
2055 	KLD_LOCK_ASSERT();
2056 	if (linker_kernel_file) {
2057 		linker_kernel_file->refs++;
2058 		error = linker_file_add_dependency(lf, linker_kernel_file);
2059 		if (error)
2060 			return (error);
2061 	}
2062 	if (linker_file_lookup_set(lf, MDT_SETNAME, &start, &stop,
2063 	    &count) != 0)
2064 		return (0);
2065 	for (mdp = start; mdp < stop; mdp++) {
2066 		mp = *mdp;
2067 		if (mp->md_type != MDT_VERSION)
2068 			continue;
2069 		modname = mp->md_cval;
2070 		ver = ((struct mod_version *)mp->md_data)->mv_version;
2071 		mod = modlist_lookup(modname, ver);
2072 		if (mod != NULL) {
2073 			printf("interface %s.%d already present in the KLD"
2074 			    " '%s'!\n", modname, ver,
2075 			    mod->container->filename);
2076 			return (EEXIST);
2077 		}
2078 	}
2079 
2080 	for (mdp = start; mdp < stop; mdp++) {
2081 		mp = *mdp;
2082 		if (mp->md_type != MDT_DEPEND)
2083 			continue;
2084 		modname = mp->md_cval;
2085 		verinfo = mp->md_data;
2086 		nmodname = NULL;
2087 		for (nmdp = start; nmdp < stop; nmdp++) {
2088 			nmp = *nmdp;
2089 			if (nmp->md_type != MDT_VERSION)
2090 				continue;
2091 			nmodname = nmp->md_cval;
2092 			if (strcmp(modname, nmodname) == 0)
2093 				break;
2094 		}
2095 		if (nmdp < stop)/* early exit, it's a self reference */
2096 			continue;
2097 		mod = modlist_lookup2(modname, verinfo);
2098 		if (mod) {	/* woohoo, it's loaded already */
2099 			lfdep = mod->container;
2100 			lfdep->refs++;
2101 			error = linker_file_add_dependency(lf, lfdep);
2102 			if (error)
2103 				break;
2104 			continue;
2105 		}
2106 		error = linker_load_module(NULL, modname, lf, verinfo, NULL);
2107 		if (error) {
2108 			printf("KLD %s: depends on %s - not available\n",
2109 			    lf->filename, modname);
2110 			break;
2111 		}
2112 	}
2113 
2114 	if (error)
2115 		return (error);
2116 	linker_addmodules(lf, start, stop, 0);
2117 	return (error);
2118 }
2119 
2120 static int
2121 sysctl_kern_function_list_iterate(const char *name, void *opaque)
2122 {
2123 	struct sysctl_req *req;
2124 
2125 	req = opaque;
2126 	return (SYSCTL_OUT(req, name, strlen(name) + 1));
2127 }
2128 
2129 /*
2130  * Export a nul-separated, double-nul-terminated list of all function names
2131  * in the kernel.
2132  */
2133 static int
2134 sysctl_kern_function_list(SYSCTL_HANDLER_ARGS)
2135 {
2136 	linker_file_t lf;
2137 	int error;
2138 
2139 #ifdef MAC
2140 	error = mac_kld_check_stat(req->td->td_ucred);
2141 	if (error)
2142 		return (error);
2143 #endif
2144 	error = sysctl_wire_old_buffer(req, 0);
2145 	if (error != 0)
2146 		return (error);
2147 	KLD_LOCK();
2148 	TAILQ_FOREACH(lf, &linker_files, link) {
2149 		error = LINKER_EACH_FUNCTION_NAME(lf,
2150 		    sysctl_kern_function_list_iterate, req);
2151 		if (error) {
2152 			KLD_UNLOCK();
2153 			return (error);
2154 		}
2155 	}
2156 	KLD_UNLOCK();
2157 	return (SYSCTL_OUT(req, "", 1));
2158 }
2159 
2160 SYSCTL_PROC(_kern, OID_AUTO, function_list, CTLFLAG_RD,
2161     NULL, 0, sysctl_kern_function_list, "", "kernel function list");
2162